Die with plastic liner



y 1962 L. s. TANNER ETAL 3,04

DIE WITH PLASTIC LINER Filed June 4, 1959 3 Sheets-Sheet 1 3 &\ Ii 1 z /8 24 /7 /.9 23

El El A W lj F i El INVENTORS LAWRENCE S.TANNER BY ALFRED LINDINGER ATTORN EYS y 1962 L. s. TANNER ETAL 3,041,989

DIE WITH PLASTIC LINER Filed June 4, 1959 5 Sheets-Sheet 2 Tim INVENTORS LAWRENCE S.TANNER By ALFRED LINDINGER ATTORNEYS July 62 L. s. TANNER ETAL 3,041,989

DIE WITH PLASTIC LINER Filed June 4, 1959 5 Sheets-Sheet 3 INVENTORS LAWRENCE S.TANNER ALFRED LINDINGER ATTORNEYS United States Patent 6 3,041,989 DIE WITH PLASTIC LINER Lawrence S. Tanner, 11300 E. 9 Mile Road, Warren, Mich., and Alfred Lindinger, 25800 Madison Court, St. Clair Shores, Mich.

Filed June 4, 1959, Ser. No. 818,135 1 Claim. (Cl. 113-49) Our invention relates to a new and useful improvement in a die and forming of same.

It is an object of the present invention to provide a die consisting of a male and female part so constructed and arranged that it may be economically manufactured, and which is durable and highly efficient in use.

Another object is the provision of a forming die and particularly, the female portion thereof.

Another object of the invention is forming a female part of the die from plastic material, sized and shaped by the male die.

Other objects will appear hereinafter.

It is recognized that various modification and changes may be made in the detail of the structure illustrated without departing from the invention, and it is intended that the same shall be considered to be but the preferred embodiment.

Forming a part of this application, are drawings in which,

FIG. 1 is a central sectional view of a female die with a cavity partially formed,

FIG. 2 is a central sectional view of the female portion of the die formed with a portion of the male die inserted therein,

FIG. 3 is a central view taken on line 33 of FIG. 2,

FIG. 4 is a view similar to FIG. 2 with the male portion of a die coated with a layer of removable material,

FIG. 5 is a transverse central view of the die portions showing the completion of the formation of the female die,

FIG. 6 is a central sectional view of the die portion showing a stamping operation,

FIG. 7 is a view similar to FIG. 1 showing a modification,

FIG. 8 is a view similar to FIG. 7 showing a further step in the construction of the female die,

FIG. 9 is a central sectional view of the female die showing it in its completed form in the modification,

H6. 10 is a plan view of the die shown in FIG. 9.

As shown in FIG. 1, we indicate a female die portion 16 having a cavity 17 formed therein leading into which is a sprue 18 and a vent passage 19. The upper portion of the die has an overhanging portion 20 and this portion 20 is formed larger than the required size so that the portion determined by the dotted line 21 would be removed by machine in a suitable operation in finishing the die 16 so that the shoulder 20 will remain as shown in FIG. 2.

In FIG. 2 we then show a male portion or punch 22 of the die inserted into the female portion and it will be noted from FIG. 3, that the punch 22 is circular in cross section. As shown in FIG. 2, the punch is centered relative to the female die so that there is a space 23 between the inner face of the shoulder or overhang 20 and the periphery of the die 22. Likewise there is a larger space 24 separating the die from the inner face of the cavity in the female portion of the die.

In FIG. 4 we have shown a view similar to that of FIG. 2 excepting that the punch 22 is provided with a coating 25 of suitable or removable material such as wax or the like. It will be noted that the periphery of the layer of the wax now engages the inner face of the overhang or shoulder 20 so that the space 23 shown in FIG. 2 is eliminated.

3,041,989 Patented July 34, 1962 In FIG. 5 we have shown the female portion 16 in an inverted position and supported by suitable spokes 26 to retain the same in the proper spaced relationship to the punch 22. When in this inverted position, molten plastic 27 is poured into the sprue 18 to completely fill the space 24 and then allowed to set, thus the face of the punch 22 will determine the inner surface of the female die but due to the layer 25 of wax, the male portion will be spaced from the female portion. When the plastic is set, the parts are separated, and the removable layer 25 of wax or the like is removed from the arm of the punch, and the parts are ready for a finishing operation. This layer 25 of removable material such as waX is of the same thickness as the metal to be operated on by the die.

In FIG. 5 we have shown a punching operation in which the metal is forced inwardly of the die cavity by the punch 22 to engage the face of the liner 27 of plastic material. As the punch is punched inwardly, the metal 28 will be brought into snug engagement with the inner face of the cavity of the female die and a draw flange 29, which may be later trimmed off, may thus be formed. It will thus be observed that the cavity in the female die 16 need not be finished but may be roughly formed and that the only finished part of the structure will be the punch or male die. This eliminates spot chipping, grinding, etc. in die making and considerably reduces the cost of die making which is to the advantage of a manufacturer who is required to periodically produce a large number of dies. The punch 22 and die 16 may be cast from any suitable metal in any suitable conventional manner. A suitable plastic for the liner of plastic material 27 is one of the thermosetting type, as for example, a phenol formaldehyde resin.

In the punching operation, the edge of the overhang 20 is the only part of the female die which is subjected to wear, but this edge may be suitably treated or hardened so that practically no Wear on the die is effected in the punching operation.

In FIGS. 7, 8, 9 and 10, we have shown a slight modification. The modification relates solely to a change of the structure insofar as the overhang or shoulder 20 is concerned. In FIG. 7 we have shown the female portion 16a of the die which is rough formed but not provided with an overhang such as the shoulder 20 of the preferred form. When the portion is formed as shown in FIG. 7, it is then cut out as at 30 to provide an annular recess. Seated in this recess are metallic ring sections 31 which are secured to the portion 16a by the screws 32. The inner faces 33 of these ring sections may be molded or machined to size. After the ring sections 31 are mounted in position, a layer 27a of plastic is deposited in the cavity as previously described for the first embodiment. When punched with the structure shown in FIG. 9, the edge 33 of the ring sections 31 will be subjected to wear. Again, these sections may be suitably heat treated and hardened to resist this wear. However, when the wear becomes excessive on the engaging faces 33 of the ring sections 31, the ring sections may be removed and replaced with new sections 31 thus affording more permanency to the structure. Experience has shown that dies constructed in this manner are economical and highly efiicient in use.

What we claim is:

A die consisting of a female portion having a cavity formed therein and open at one end and formed from a block of suitable material, the face of said die at said end being cut away inwardly from the inner face of said cavity and a metallic wear resistant ring mounted on said cut away portion and extending inwardly from the inner face of said cavity, said ring being formed in sections, the inner face of said cavity being lined with a hardened plastic material terminating at its inner face flush with the inner face of said ring sections and positioned below said ring sections.

References Cited in the file of this patent UNITED STATES PATENTS 1,561,770 Berry Nov. 17, 1925 1,868,788 Zinser July 26, 1932 2,717,422 Rowe et a1. Sept. 13, 1955 

